George h



(No Model.)

G. H. GLASS & W. CLARK.

v TELBPHONIG SIGNALING AND SWITCHING SYSTEM. No. 340,911.

Batented Apr. 27, 1886.

WITNESSES IJV'VE TORJ .Httorne N PETERS, Phalo-Ulhqnphcr. Wnhinllm. D. c.

UNITED STATES PATENT OFFICE.

GEORGE H. GLASS AND WVALTER CLARK, OF RALEIGH, NORTH CAROLINA.

TELEPHONIC SIGNALING AND SWITCHING SYSTEM.

SPECIFICATION forming part of Letters Patent No 340,911, dated April 27,1886.

Application filed May 13, 1885. Serial No. 165,385. (No model.)

To all whom it may concern.-

Be it known that we, GEORGE H. GLASS and WALTER CLARK, of Raleigh, in the county of Vake and State of North Carolina, have invented certain new and useful Improvements in Telephonic Signaling and Switching Systems; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use the same.

Our invention has reference to systems and devices for service in telephone signaling and switching; and it consists in an arrangement of main and local circuits and automatic switch device in connection therewith, whereby the head or receiving telephone of the attendant may be readily included in the main circuit to receive the vocal calls of the signaling subscriber, while the main or exchange signaling bell will be sounded in its local circuit by the said subscriber to insure response to the call should the headtelephone be unattended or removed, as at night.

In the accompanying drawing, forming part of this specification, the figure represents a diagrammatic view of an arrangement of main and local circuits and devices included therein to represent our invention.

N refers to the battery of the main line, having one pole grounded, as usual, and the other led to line bya wire, G, upon which the subscribers are located. The line-wire G is led through the central office or exchange and through an automatic switch device located therein. This said switch device consists of a casing within which is secured one end of a lever, A, the other end of which projects through an openingin the casing, and is hooked at its end to enable the receiving-telephone to be hung thereon, a contracting spring, a, which is attached to the inner end of said lever A, and to a projection on the bearing of the said lever, thereby normally tending to throw said lever up into a horizontal position tocontact with two circuit'stops, G H, with which connect the wires G H of the line. Beneath the lever A are located two stops, 0 D.

F refers to the battery of a local circuit composed of the wires K L, each of which leads from the battery to the signal or night bell M,

and thence to the local circuit-closing device J. The said circuit-closing device consists of an electro-magnet, 'W, the coils of which are included in the main circuit.

6 refers to an armature located adjacent to the cores of the magnet W, but held out of contact therefrom and a circuit-terminal, c, by means of a spring, k.

The wires K L connect, respectively, with an armature, b, and contact 0, as represented.

The wire 0, after passing through the cir cuit-breaking instrument E, makes connection with the local circuit-wire L, while the wire D makes a direct connection with a wire, L, on the other side of the battery-wires G D, thus forming a sub or derived circuit for operating the circuit-breaker E. By hanging the telephone B on the lever A, the latter closes said derived circuit.

In the day, or during the period when the attendant is using a head-telephone, of course the receivingtelephone B is hung on the lever A, thereby breaking the main line. The head-telephone is therefore included in the main-line circuit at R, as represented by dotted lines, so as to bridge the wires G H, and thus perfect the said line;

The circuit-breaker E may, in its general form, be like that set forth and described in our application N 0. 169,505, filed June 23, 1885. By referring to the drawing it will be noted that the wires 0 G are in circuit with the coils of the magnet c, which operates the armature of the circuit-breaker, the said armature being designed to make and break the circuit formed by the wires :0 y, the wire y connecting with the contact g, while the wire a; connects with the armature of the circuitbreaker. The wires j form a short circuit through the armature to cut out the magnetcoils when the armature contacts with the contact g. It will therefore be seen that by hanging the telephone upon the lever A the magnet-circuit formed by the wires 0 D L and battery F will operate the armature of the circuit-breaker E to make and break the circuit formed by the wires as y and battery N, and the rapid making and breaking of the line at the point 9, by opening and closing the short circuit around the battery N, rings the subscribers bell. The subscriber (represented at I) grounds his instrument, as represented by dotted lines, and any vocal calls or signals made by him can be readily heard by the attendant at the main office. At night, however, when the attendant is away from the switching device, the head -telephone is of course removed from the main line and the receivingtelephone B removed from the lever A and placed on a shelf or other adjacent support. of the weight of said telephone, and under'the action of the spring a move up in contact with the points G H, thereby completing the main line. Now, when the subscriber I desires to call the main office he pulls down the lever of his transmittinginstrument, thereby indnc ing a current to flow from battery N onto the main line G, thus magnetizing the magnet WV, attracting the armature b to contact with c, and thereby close the local circuit, causing the ringing of the bell M.

From the foregoing it will be apparent that by employing the switch device herein described an automatic arrangement is provided that will readily accommodate itself to the various conditions required, and will not be open to the objections incident to the handoperated switch devices heretofore employed. Moreover,the signaling of thesubscriber causes the main circuit to automatically close the 10- cal circuit and sound the night-bcll.

The lever A will then be relieved- By including the head receiver in the main line, and hanging the receiver B on the lever A, vocal calls of the subscriber wirl be heard by the attendant, and the employment of the night-bell M will be dispensed with.

\Ve claim- 1. The combination, in a telephone signaling system, of a main line, a local circuit having a circuit-breaker included therein, to make and break for signaling purposes, a distinct circuit around the signaling-battery, and a le ver adapted to interrupt said first-mentioned circuit when a telephone is hung thereon, and complete the local circuit, substantially as described.

2. The combination, in a telephone signaling system, of a main line, a switch device in cluded therein andhaving a lever adapted to interrupt said main line when a receivinginstrument is hung thereon, and a head receiving-instrument designed for connection with said line to bridge or complete the same, substantially as set forth.

.In testimony whereof we have signed this specification in the presence of two subscribing witnesses.

GEO. H. GLASS. \VALTER CLARK. \Vitnesses:

J. L. SEAWELL, I. I. THOMAS. 

